Nasal steroid spray only (NS) (Each dose contains 27.5 micrograms of fluticasone furoate; administered single dose per day as 1 puff through both nostrils)

NS + administered ambient temperature normal saline (NSS) through both nostrils by means of nasal douche device twice a day 15 minutes before NS. (NSS; 0,09% NaCl, pH:4-5)

NS + administered ambient temperature hyaluronic acid (HA) through both nostrils by means of nasal douche device twice a day 15 minutes before NS. (Nasorinse plus pediatric® Ingredients: water, sodium chlorine, sodium bicarbonate, and HA; pH balanced)

TNSS contains 4 parameters in assessing the severity of allergic rhinitis: nasal congestion, runny nose, nasal itching, and sneezing. Each symptom is scored out of 4 points, from 0 to 3. 0, none- there are no complaints 1- mild- any symptom that exists but is not particularly annoying; 2, moderate, - any annoying symptom but does not interfere with daily activities or sleep; 3, severe - any symptom preventing daily activities or disturbing during sleeping. The total score is calculated by summing all the scores of 4 fields, which vary ranges from 0 to 15 .In our study, all patients will be instructed to record their TNSS symptom scores on their diary cards each morning before taking the drug. Patients will be graded on baseline TNSS parameters compared to 4 weeks before starting treatment.

The primary outcome will be to understand whether nasal irrigation with hyaluronic acid (HA) solution will be beneficial as add-on therapy in children who are already receiving nasal steroid (NS) therapy.

Total Nasal Symptom Scores (TNSS) of all participants (the study and control groups) will be used in grading the symptom relief of seasonal allergic rhinitis.

Each symptom (nasal congestion, runny nose, nasal itching, and sneezing) will be graded from 0-3 (0=None, 1=Mild, 2=Moderate, 3=Severe) by the participants during the screening. No special unit for the scoring system is identified according to TNSS (Only scores mentioned with numbers will be analyzed with SPSS, and the percentages of symptoms will be the primary outcome).

PRQLQ is a self-administered, disease-specific questionnaire and the survey contains 23 items in 5 domains: nose symptoms (RS), eye symptoms (ES), practical problems (PF), activity limitation (RL) and other symptoms (OS). One score is given to each domain. 7-point scale (from 0, not problematic; to 6, very problematic). The overall score will be derived from the average score of all items.

No special unit for the scoring system is identified according to PRQLQ (Only scores mentioned with numbers will be analyzed with SPSS, and the percentages of symptoms will be the primary outcome 2).

• Nasal cytology in anterior rhinoscopy, the middle part of the lower concave will be scraped with the help of a small sterile cotton swab. Slides will be first screened under microscopes to determine the adequacy and cellular areas of the sample at 100 magnification. Slides will be dripped immersion oil and screened under an optic microscope x 1.000 magnification equipped with a digital camera. Analysis of rhino cystograms will involve screening at least 50 fields (300 cells). A percentage of the cell per 100 cells will be reported. NECs (nasal eosinophilic count) will be evaluated according to quantitative classification system described previously by Gelardi et al. Grade 0: No cell; Grade ½: 0,1-1% Eosinophil; Grade 1: 1.1-5% Eosinophil; Grade 2: 5-15% Eosinophil; Grade 3: 15-20% Eosinophil; Grade 4: > 20% Eosinophil. Eosinophil percentages in nasal smears of all patients will be evaluated before and at the end of treatment.